Philips DVP3126K Service Manual page 14

Disc cannot be read .
Check
voltage (2.3V for DVD and 1.9V for
CD) on Collector of Q2 &Q3
Check if there is RFO signal on
pin10 of CN2. (The normal RFO
signal is a clear reticulated wave)
Disc cannot be read.
Yes
Check the FFC connection
between 24P and the loader.
Yes
whether there is
Yes
Check U1, U7, and
peripheral components are
eroded or badly soldered.
Yes
Yes
Check the connection
between U1
Yes
Replace U1 or loader.
4-4
No
1.Check voltage on pin 100 of U1
laser
varies between 0 and 3.3V:
No
2.Check
No
Re-solder or replace the defective parts
No
No
Trouble shooting chart
Check the loaded circuit
3.3V for CD
0V for DVD
whether peripheral
Check U1 and peripheral components
Correct connection